Preliminary O15 PET scan data from 11 men with severe developmental dyslexia and matched controls shows differences in left perisylvian blood flow in both the resting state and while performing neuropsychological tests which activate language realted areas in normal controls. An MRI study of the planum temporale and corpus callosum on this same group of patients is nearly complete. A genetic study of one large pedigree with a high incidence of dyslexia shows evidence of linkage to chromosome 6, a result similar to that seen in other dyslexic families. Neuropsychological studies of executive functions and social-perception continue in high-functioning (i.e., nonretarded) adults with autism. Neuropsychological, MRI, neurological and genetic studies of savants with calendar calculating skills, many of whom are autistic, have begun.